Adjusting screw



J. F. TRITLE ADJUSTING SCREW Oct. 14, 1930.

Original Filed Sept. 7, 1927 Ifivehbor':

John F'- Triple,

(0%- Abner-he' Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE JOHNF. TRI'ILE, OF ERIE, PENNSYLVANIA, .ASSIGNOB TO GENERAL. ELECTRICCOMPANY, A CORPORATION OF NEW YORK ADJUSTING SCREW Original applicationfiled September 7, 1927, Serial No. 218,095. Divided and thisapplication filed July This application is a division of my applicatipnSerial No. 218,095, filed September 7, 192

The present invention relates to adjusting screws for positioningrelatively movable members, and more particularly to adjusting screwsadapted for positioning the contact fingers of a drum controller or foruse in any other similar service.

The principal object ofthe present inven tion is to provide an improvedform of adjusting screw for service of the above character adaptedreadily to permit intentional adjustment of the screw whenevernecessary, and at the same time insure that the adjusting screw issecured against accidental misadjustment by jars and vibration.

In accordance with the present invention the adjusting screw is screwthreaded into one of the relatively movable members to be adj usted andis provided with a spring washer and a cooperating friction locking diskfor preventing accidental misadjustn ent of the screw while readilypermitting intentional adjustment thereof.

In the accompanying drawing Fig. 1 is a perspective view of a drumcontroller contact finger provided with an improved adjusting screw inaccordance with the present invention and Fig. 2 is a cross sectionalview showing more in detail the manner in which the adjusting screwisapplied to the contact finger.

As shown in Fig. 1 the adjusting screw 10 is arranged to adjust thecontact arm 11 with respect to the channel housing support 12. Thecontact arm 11 is pivotally mounted at its right hand end for operationbetween the sides of the channel housing support 12 and the biasingspring 13 serves to maintain the contact finger in the desired positiondetermined by adjustment of the screw 10. The detailed construction andadvantageous features of the particular form of contact fingerillustrated are fully set forth and claimed in my previously mentionedapplication and no further detailed description is deemed necessary asthe adjusting screw arrangement of the present invention is notnecessarily limit- Serial No. 291,903.

ed to use with such contact fingers but may be applied generally.

As shown more in detail in Fig. 2, the adjusting screw 10 is screwthreaded into the movablev contact arm 11 with its lower end resting onthe reinforcing rivet let provided on the lower side of the channelhousing support 12 for the contact finger. Adjustment of the screw 10serves to raise or lower the contact arm 11 into the desired operatingrelation with the cooperating controller drum indicated diagrammaticallyin Fig. 2. The adjusting screw 10 is prevented from turning from anyposition to which it is adjusted by means of the large diameter splitspring lock washer 15 which may be of standard form as illustrated andthe cooperating friction locking disk 16. The locking disk 16 is screwthreaded on the adjusting screw 10 and the projecting circular shoulderor boss 17 formed on the lower side of the disk 16 serves to maintainthe lock washer 15 coaxially with the adjusting screw 10 even though thespring lock washer is oi much greater diameter than the screw 10.

In assembling the adjusting screw and the locking means therefor, thelocking disk 16 is run to the top of the screw threads on the adjustingscrew 10 and the screw 10 is then screwed into the threaded opening inthe contact arm 11 with the spring lock Washer 15 in position to fitover the shoulder 17. Upon tightening the screw 10 the disk 16 rotateswith the adjusting screw 10 and thereby compresses the split spring lockwasher 15. Thereupon the adjusting screw 10 may be un screwed to adjustthe position of the contact arm 11 as desired without producing rotationof the locking disk 16. This is due to the fact that the frictionalengagement of the split spring lock washer 15 with the disk 16 at theincreasedradius of the shoulder 17 produces a greater friction than thatexisting between the threads of the disk 16 and the adjusting screw 10.However, this thread friction serves effectively to prevent accidentalmovement of the adjusting screw 10 from its adjusted position due tovibration or other causes.

Vhat I claim as new and desire to secure by Letters Patent of the UnitedStates, is 2-- The combination of relatively movable members, anadjusting screw therefor in threaded engagement with one of the members,a locking member screw threaded on said adjusting screw in spacedrelation with said one member, and a spring lock washer of materiallylarger diameter than the adjusting screw interposed between said onemember and said locking member for preventing aecidenta rotation of theadjusting screw while readily permitting adjustment thereof, saidlocking member having a circular shoulder termed on the side thereofengaging with said spring washer for maintaining the washer coaxial withthe screw.

In witness whereof I have hereunto set my hand this 9th day of July,1928.

JOHN F. TRITLE.

